Water Resource Modeling in Egypt

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Water Resource Modeling in Egypt
Dr. David A. Wiberg Task Force on Population,
Human Capital, and Water in Egypt August 9-10,
2004 IIASA, Laxenburg, Austria
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Water Scarcity Indicators
Indicator Scarcity Value Egypt
Renewable Water Resource/Population (m3/cap) lt 1000 830
Use/Availability gt 0.4 1.3
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Sample Modeling Approach
Climate Scenario
Hydrologic Model (Rainfall/Runoff)
Crop Model
Water Routing/ Management Model
Economic Model
Population Socio-Economics
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Climate Scenario Methods

• Historical analogues
• Spatial analogues
• Mathematical climate models such as global
  circulation models (GCMs), and regional
  circulation models (RCMs)

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Hydrologic Model Structure
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Routing/Management Model
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Crop Model Example AEZ
Suitability for rain-fed and irrigated cotton
(high inputs) Africa
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The International Linkage in the World Food
System Model
18 national models,2 country-group models,14
regional modelsCommodities wheat, rice, coarse
grains, protein feed, bovine ovine meat, dairy
products, other animal products, other food,
non-food agriculture, non-agriculture.Linkage
trade, world market prices and financial flows
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Climate Change Impacts on Reservoir Operation

• The Effect of Changing Mean and Variance of
  Inflow Time Series

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Method

• Models Used
• GCMs (GFDL and GISS)
• Ratio and difference methods
• Precipitation-runoff model (WatBal)
• Stochastic ARMA model (SAMS)
• Mean and variability changed.
• Flow model (WOW)
• Historic values for everything except inflow used.

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Scenarios

• Historic
• mh, sh
• mh, 0.5 Wh 0.5 sh/ mh
• mh, 2 Wh 2 sh/ mh
• GFDL
• mgfdl, sh
• mgfdl, 0.5 Wh 0.5 sgfdl/ mgfdl
• mgfdl, 2 Wh 2 sgfdl/ mgfdl

• GISS
• mgfdl, sh
• mgfdl, 0.5 Wh 0.5 sgfdl/ mgfdl
• mgfdl, 2 Wh 2 sgfdl/ mgfdl

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Stochastic Model Results
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Reservoir Impact Results

• Reservoir parameters analyzed
• Number of water shortages (drought)
• Amount of spill (inefficient water use)
• Number of dam overtoppings

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Number of Drought Periods
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Number of Overtoppings
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Volume of Spill
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Analysis

• Impact of mean
• Storage curve shifts up or down, causing spill or
  shortage
• Possible Remedies
• Increase or decrease releases
• Problems
• May have to increase maximum release and maximum
  spill

• Impact of variability
• Wider swings cause both spill and shortage in the
  same series
• Possible Remedies
• Increase storage capacity
• Problems
• Structural change necessary. Severe consequences.

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Conclusions

• Changing climate variability is more difficult to
  deal with than changing climate means and should
  be included in any climate change study.
• Mean changes can possibly be dealt with by simple
  changes in operating policy
• Climate variability changes require more
  difficult structural changes and better
  preparation.

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Sample Modeling Approach
Climate Scenario
Hydrologic Model (Rainfall/Runoff)
Crop Model
Water Routing/ Management Model
Economic Model
Population Socio-Economics
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Future Directions

• Improve modeling.
• Water Quality (water quality associated with
  demand)
• Location and quality of return flows
• Water supply/treatment costs
• Impact of water use efficiency on system
• Land degradation and subsidence
• Water use data necessary
• Include future water demand projections.
• Link routing/management model to economic model
  to optimize operating policies for present and
  future conditions.